Evolution of Energy Crops Tolerant to Water Deficits

12/5/2017 12:00:00 AM

A recent research by the Department of Energy's Oak Ridge National Laboratory has affirmed the existence of a common set of genes found in different drought-resistant plants. The genes help in survival of these plants in areas that receive less than 20 inches of rain each year. These genes have played a remarkable role in the bioengineering and creation of energy crops that can tolerate water scarcity. The scientists are trying to discover the mystery of Crassulacean Acid Metabolism or CAM Photosynthesis, by examining a range of drought resistant plants.

CAM photosynthesis is a technique used by plants to flourish in dry lands. To accomplish their study, the team led by ORNL, sequenced the genome of Kalanchoe fedtschenkoi. The team used ORNL's Titan supercomputer so as to compare the genomes of K. fedtschenkoi, Phalaenopsis equestris (orchid) and Ananas comosus (pineapple). They identified 60 genes in the CAM species that displayed convergent evolution. Convergent evolution is a process wherein unrelated plants show, like characteristics under like environmental conditions.

Particularly, the team identified a new variety of phosphoenolpyruvate carboxylase, or PEPC. PEPC is a worker enzyme that helps in night time fixation of carbon dioxide into malic acid. This malic acid is again converted to Carbon- dioxide during the day for photosynthesis. In order to gear up the development of water use efficient plants, the convergent changes in gene expression and protein sequences must be introduced into plants relying on traditional photosynthesis.